OK, maybe another approach (rather than doing Google searches) would be to look on the Alaska Fish and Game web site to see if they have a listing of lodge or guide operators.
Edit: Well that didn't turn up anything, I found the F&G web page listing the requirements for becoming a guide but that was it. How about calling the folks at the Little Mulchatna Lodge to see if they know who their neighors are down stream (see the orginal link, it lists their phone number)? If that doesn't turn up a lead, how do lodges advertise for clients in Alaska? Maybe looking through that source would turn up that lodge you are looking for.
Ok, I found another outfit operating on the Mulchatna river, MULCHATNA WILDERNESS LODGE, maybe this is the outfit you are looking for, if not they also list a phone number and email addy at the bottom of the page.
If the above doesn't help, I found a web page talking about a guy named John Rydeen that used to guide on the Mulcchatna River, he might know the name of the lodge you are seeking information on. Scroll to the bottom of this page and you will see what I'm talking about. http://www.katmai-wilderness.com/staff.php